Flatlock looper locking and adjusting means



March 27, 1951 2,546,177

F. P. TAMBURRO FLATLOCK LOOPER LOCKING AND ADJUSTING MEANS Filed Ot. 24,1946 2 Sheets-Sheet l March 27, 1951 F. P. TAMBURRQ 2,545,177

FLATLOCK LOOPER LOCKING AND ADJUSTING MEANS Filed Oct.` 24, 1946 2Sheets-Sheet 2 INVENTOR. jW/mncfld Tamz/ma BY A T TOR/VE' VLB' PatentedMar. 27, 1951 FLATLOCK LOOPER LOCKING AND ADJUS'IING MEANS Francis P.Tamburro, Ozone Park, N. Y., assignor to Willcox & Gibbs Sewing MachineCompany, New York, N. Y., a corporation of New York Application October24, 1946, Serial No. 705,423

14 Claims. l

'I'his invention relates to sewing machines, and more particularly tolooper mechanisms of sewing machines.

An object of the invention is to provide an improved looper mechanismwhich enables quick, accurate and convenient adjustment of the loop erswith respect to the machine needles.

The invention is shown as applied to what is commercially known as theWillcox & Gibbs Sewing Machine Companys Flatlock machine, although itshould be understood that it is applicable to sewing machines generally,and is not to` be limited to the specic embodiment illustrated herein.

= In the above-mentioned Flatlock machine, which isv an ol-the-armmachine and is shown in Pat. No. 1,041,652, issued to A. A. Merritt onOctober 15, 1912, the loopers which cooperate with the needles and whichare carried in the work-supporting arm, are mounted on the end of apivoted carrier which is latched to the end ofthe looper lever, thelatter at its other end being driven through a bell-crank, a verticalpitman and a horizontal pitman from the looper crank of the main shaftin the machine. Both the horizontal pitman and the vertical pitman pivotintermediate their ends about pinssecured to the machine frame, thepivotal connection also constituting a sliding connection by virtue ofthe pins mounting slide blocks which engage the Walls of slots in thepitmans.

In this prior construction, for thepurpose of adjustably positioning theloopers with respect to' ,the needles so as to obtain a predeterminedrelationship between these, the pivot pins of both the horizontal andthe vertical pitmans are ,conswt'ructed so as to be eccentric, and arerotatably adjustable. The path of travel of the loopers is substantiallyelliptical, and adjustment of the eccentric pivot pin for the Verticalpitman changes the magnitude of the minor ax's of the ellipse, andadjustment of the eccentric pivot pin forthe horizontal pitman changesthe magnitude of the major axis of the ellipse. According to this priorconstruction, however, adjustment of one of the eccentric pins to changethe magnitu'de of one of the axes of the elliptical path also results inthe shifting of the other axis of the ellipse, and therefore it requireda certain amount of skill to obtain the proper relationship between theloopers and the needle. g

vvThe adjustment involved not merely a single turning of one eccentricpivot pin and then a single turnngof` the other eccentric pivot pin,

but instead involvedv a series of alternate turn-fv adjustments, whichcould be made from the ex" terior of the machine, were taken care of itwasfound that the spreader of the machine had toi4 j be readjusted dueto the new position of the As a result, the complete adjust-ly ment ofthe loopers was quite difcult and time-n looper lever.

consuming.

This diculty is obviated by the present in-f vention by eliminating theeccentric pivot adjustment which controls the magnitude of the minorlaxis of the elliptical path, such adjustment being associated with theVertical pitman of the looper, drive, and by providing instead forlateral adjustment oi the loopers by shifting these relative-- This isaccomplished in ly to the looper lever. the specic embodiment of theinvention illustrated herein by providing a movable lock or latch plateon the end of the looper lever, whichv plate cooperates with a lockinglatch pin and heretofore was xedly positioned on the looper lever.

In adjusting the latch plate, a screw which normally holds the platelocked in adjusted position is loosened, and then an adjustment screwengaging the plate and threading into the end of the looper lever isturned, so as to shift the latch plate horizontally and edgewise. Thisshifting of the latch plate moves the looper' carrier or bar on whichthe loopers are mounted, and thus shifts the loopers laterally one Wayor the other until the desired position is obtained.

The screw which locks the latch plate in ad-' justed position may beoperated by a screw driver passed through an aperture in the end of thework-supporting arm; the adjusting screw for LEC' the latch plate may beturned by a tool inserted in the large front opening of theWork-supporting arm, which is normally closed over by a swinging coverplate.

The lateral adjustment of the loopers may be very line, so that aprecise positioning of these with respect to the needles of themachine'is had, and such positioning is independent of ad` justment ofthe eccentric pivot pin associated with the horizontal pitman and whichcontrols the magnitude of the major axis of the elliptical path.

As a result, since the lateral and longitudinal looper adjustments areindependent of each other the loopers may be quickly and accuratelypositioned with respect to the needles of the machine, and also may besecurely locked in their adjusted positions.

The structure bywhich thev adjustment of the` 'tures in the loopers 31,and

loopers on the end of the looper lever is accomplished is extremelysimple and sturdy so that it withstands the high sewing speedsencountered in use of the machine, and this is a feature of theinvention. 1

Other features and advantages will hereinafter appear.

In the accompanying drawinjs:

Figure 1 is a front elevation of a sewing machine embodying theinvention.

Fig. 2 is a vertical fragmentary section taken on the line 2-2 of Fig.1.

Fig. 3 is a fragmentary vertical section taken through the end of thework-supporting arm of the machine.

Fig. 4 is a perspective view of the loopercarrying end of the looperlever.

Fig. 5 is a view like Fig. 4 but showing the looper carrier swungforwardly on the lever, and

Fig. 6 is an exploded view of the end of the looper lever.

Referring to Fig. 1 the above-mentioned Willcox & Gibbs Flatlock machinecomprises a base IE) supporting a vertical post II which carries anoverarm I2 on the end of which a sewing head I3 is mounted. `As shown inFig. 2, the vertical post II also carries a forwardly extendedhorizontal portion I5 joining with a vertical depending portion I5mounting at its lower end the work-supporting arm I1, which latterextends angularly rearward so that its free end is positioned below theusual needles (not shown) and sewing head I3.

Referring to Fig. 3 the work arm I1 carries a looper lever I8 within it,the said lever extending longitudinally of the arm and having a mountingI9 which enables it to have both a pivotal movement and a longitudinalsliding movement. As shown in Fig. 2, one end of the looper lever I8 hasa trunnion 28 which is connected to a bell-crank 2I carried by pivots 22on the depending portion I6 of the machine frame. The other arm of thebell-crank 2I is connected to the lower end of a vertical pitman 23which is mounted for both pivotal and longitudinal sliding movement on apivot pin 24 carrying slide blocks 25 which ride in a slot 2G in thepitman. The upper end of the pitman 23 is connected with a horizontalpitman 21 which is mounted for pivotal and longitudinal sli-dingmovement on a pivot pin 28 carrying slide blocks 29 engaging the wallsof a slot 3U in the pitman. The horizontal pitman 21 at its other endhas a bearing 3l by means of which it is connected to and driven fromthe looper crank 32 of the main shaft of the machine.

According to the above organization rotation of the main shaft of themachine will impart to the free end 33 of the looper lever an ellipticalmovement which is commonly termed a fourdirectional movement in thetrade.

f Referring to Figs. 4 and 5, the free end 33 of the looper lever I8car-ries a pivot screw 34 by which a looper carrier in the form of aflat bar 35 is mounted. The carrier 35 has a pair of upstanding arms 35between which are clamped a plurality of loopers 31 by means of screws38. The said screws also carry a plate 39 having threadreceivingapertures 48 which guide the threads respectively to the loopers 31. Thelooper carrier 35 is shown in operative position in Fig. 4; it maybeswung to a forwardly extended position as shown in Fig. 5 for thepurpose of passing threads through the guide plate 39 and through theaperfor purposes of inspecting loopers etc. i

In order to rigidly hold the looper carrier 35 in the operative positionof Fig. 4, and to enable the carrier to be conveniently and quicklypivoted forward a latch mechanism is provided, comprising a lock pinorplunger 4I which is axially movable in the carrier 35 and is connectedwith a fingerpiece 42 extending laterally from the carrier for easyactuation. The plunger 4I is springurged outward and is receivable in anaperture 43 in a lock plate 44 which is secured to the free end 33 ofthe looper lever I8.

Referring to Fig. 4, the elliptical movement which is imparted to thefree end 33 of the looper lever IS results in the loopers 31 travelingin an elliptical path as indicated by the broken line 45. This path maybe considered as having a minor axis indicated by the line 46-45, and amajor axis indicated by the line 41--41.

kFor the purpose of changing the magnitude of the portion of the majoraxis 41--41 which is included in the elliptical-path 45, the pivot pin28 for the horizontal pitman 21 may be made eccentric, as disclosed inthe Merritt patent identifiedabove. By rotatably shifting the eccentricpivot pin 28 the amount of travel or stroke of the end 48 of thehorizontal pitman may be changed, and this changes the magnitude of theincluded portion of the major axis 41--41 of theellipitical path 45, asis well understood.

The structure as thus far described is conventional and well-known inthe above-identified Flatlock sewing machine.

In accordance with the present invention means are provided, in the formof an adjustable mounting for the latch plate 44 on the end 33 of thelooper lever, for laterally shifting or adjusting the loopers 31 withrespect to the lever end 33. In accomplishing this, referring to Fig. 6,the end 33 of the looper lever is provided with a horizontal groove 49,and the latch plate 44 is provided with pins or lugs 50 which arepunched from and project inwardly and extend into the groove 49. Alsothe latch plate 44 has an oval hole or slot 5I which receives a lockingscrew 52, the latter being threaded into a hole 53 in the end of thelooper lever'and rigidly securing the latch plate to the lever in anyadjusted position.

For the purpose of providing minute adjustment of the latch plate 44 thelatter is provided with a bifurcated arm 54 which encompasses anundercut portion 55 of an adjusting screw 56 threaded into a hole 51 inthe side of the looper lever I8. The undercut portion 55 of the lockingscrew 56 is adjacent the head thereof, the arrangement is such thatthreading in of the adjusting screw will drive the bifurcated arm towardthe lever end 33 and threading out of the adjusting screw will drive thebifurcated arm away from the free end 33, Thus, when the locking screw52 is loosened slightly, turning of the adjusting screw 55 will shiftthe latch plate 44 edgewise and horizontally with respect to the leverend 33.

When the looper carrier 35 isl in its operative position as shown inFig. 4, adjustment of the latch plate 44 will result in the loopercarrier 35 and loopers 31 being shifted laterally with respect to thelever end 33. This shifting results in a shifting of the includedportion of the minor axis 46-46 of the elliptical path 45 of theloopers, and therefore controls the lateral movements or stroke of theselatter. Upon the proper lateral positioning of the loopers with respectto the needles being obtained, tightening of the locking screw' 52561111securely lock the'lopers to the lever arm in adjusted position. l

This is in contradistinction to the adjustment heretofore provided forshifting the loopers .31 laterally, which adjustment was effected bymaking the pivoting pin 24 for the vertical pitman 23 eccentric androtatably adjustable. Such prior adjustment always resulted in upsettingof the adjustment of the looper as provided by turning of the eccentricpivot pin 28. l

. It will be seen that such lateral adjustment of the loopers 3l asaccomplished by turning of the adjusting screw 56 is independent of theadjustment effected by turning the eccentric pivot .pin 28, since itdoes not disturb the longitudinal path of travel of the loopers, norchange in any way the magnitude of the included portionof the major axis41-41 of the elliptical path 45, and this 'is a great .advantagesince'it enablesrv the proper relationship between the loopers 31 'andneedles being attained with but very few adjustments, and with speed andaccuracy.

By the provision of the slot 49 in the end 33 of the looper lever, andthe guide pins 50 which enter the said slot, the latch plate 44 isalways maintained in its true upright position, regardless of itsadjustment. This upright position is alsozmaintained by a close fitbeing provided between the bifurcated arm 54 and the undercut portion 55of the adjusting screw 56. n For the purpose of enabling the lockingscrew 52 to be easily reached by a screw driver, the end of the work armIl has an opening 58 in alignment with the screw end and of a size toadmit a, screw driver. Also, it willbe understood that swinging open ofthe cover plate' 59 which is normally provided on the front of the workarm Il will enable access to be had to the adjusting screw 56.

As shown in Fig. 3, the loopers 3l extend under the conventional feeddogs 60 of the machine, as"

does also a spreader plate 6I which is pivotally mounted on the work armI1 and driven by a cam segment 62 carried by the looper lever I8.

The lateral adjustment of the loopers 3l with respect to the looperlever I8 as provided by the-organization described above, obviates thenecessity of 'readjusting the spreader 6l rwhich readjustment waspreviously necessary when adjusting the loopers by means of twoeccentric pivot pins associated with the pitmans. In the appended claimswhere the term major axis.and minor axis are used in connection with theelliptical path of travel ofthe loopers 3l these terms are intended tosignify the portions of these axes which are included within the saidpath of travel. lx.Variations and modifications may. be made within thescope of this invention and portions of the improvements may be -usedwithout others. i EI claim;

l. In'a sewing'machin'e, a looper lever; a looper carriedv by the looperlever; means for driving the looper lever in coordination with theneedle-actuating mechanism of the machine, the said driving meanscausing the looper to travel in an elliptical path; means associatedwitnthe looper lever driving means for changing the path of travel ofthe llooper to vary the magnitude of the major axis of the ellipticalpath thereof; and adjustable means operative to positively shift thelooper laterally on the looper lever so as-to--alter the path of` travelof the looper and change thev relative position of. the minor axis ofthe said elliptical path.

for changing the elliptical path of travel of thel looper by changingthe magnitude of the major axis of the said path; and means connected.with the latch mechanism for shifting the looper carrier and looper withrespect to the looperlever so as to alter the relative position of theminor' axis of the said elliptical path of travel. 1 3.'In a sewingmachinefa looper" lever; a' looper carried by the looper lever; meansin-;' cluding a pitman for driving'the looper lever inv coordinationwith the needle-actuating mechanism of the machine, the said drivingmeans causing the looper to travel in an elliptical path the major axisof which is a function of the leverage ratio of the pitman; meansassociated with the looper lever driving means for changing the path oftravel of the looper to vary the magnitude of the major axis of theelliptical path thereof, the said means including an eccentric pivot pinassociated with the said pitman; and adjustable means operative topositively shift the looper laterally on the looper lever so as to alterthe path of travel of the looper and change the relative position of theminor axis `.of the said elliptical path.

4. In a sewing machine, a looper lever; a looper carried by the looperlever; means for driving the looper lever in coordination with theneedle-actuating mechanism of the machine, the said driving meanscausing the looper to travel in an elliptical path; means associatedwith the looper lever driving means for chan-ging the path of travel ofthe looper to vary the magnitude of one of the axes of the ellipticalpath thereof; and means coupled with the looper and operative topositively shift the looper on the looper lever so as to alter the pathof travel'of the looper and change the relative position of the otheraxis of the said elliptical path.

5. In a sewing machine, the combination with a needle andneedle-actuating mechanism, of a looper lever; a looper carrierpivotally mounted on the looper lever; a looper on the looper carrier; amanually operable latch mechanism normally holding the looper carrier ina predetermined operating position on the looper lever; means includinga pitman for driving the looper lever from the needle-actuatingmechanism of the machine to cause the looper to travel in an ellipticalpath; means associated with the looper lever driving means for changingthe elliptical path of travel of the looper by changing the magnitudeVYof the'major axis of the said path, the said means including anadjustablev eccentric pivot pin for the said pitman; and means connectedwith the latch mechanism for shifting the looper carrier and looper withrespect to the looper lever so as to alter the relative position of theminor axis of the said elliptical path of travel.

6. In a sewing machine, the combination with a needle andneedle-actuating mechanism, of na looper lever driven in coordinationwith the actuating mechanism; a loopercarrier pivotally mounted on thelooper lever; a looper'on` the 'Z looper carrier; a manually operablelatch mechanism normally holding the looper carrier in a predeterminedoperating position on the looper lever; and means connected with thelatch mechanism for moving and shifting the looper carrier and looperwith respect to the looper lever so as to obtain a predeterminedrelationship between the looper and needle.

7. In a sewing machine, the combination with a .needle andneedle-actuating mechanism, of a looper lever; means for driving thelooper lever in coordination with the actuating mechanism; a loopercarrier pivotally mounted on the looper lever; a looper on the loopercarrier; a manually operable latch mechanism normally holding the loopercarrier in a predetermined operating position on the looper lever; meansassociated with the looper lever driving means for changing the path oftravel of the looper lever; and means connected with the latch mechanismfor shifting the looper carrier and looper with respect to the looperlever so as to obtain a predetermined relationship between the looperand needle.

8. In a sewing machine, a looper lever driven in coordination with theneedle-actuating mechanism of the machine; a looper carrier pivotallymounted on the looper lever; a looper on the looper carrier; a manuallyoperable latch mechanism having an anchoring part mounted on the looperlever and normally holding the looper carrier in a predeterminedoperating position on the lever; and means for shifting the anchoringpart ofthe latch mechanism with respect to the looper lever to alter theposition of the looper carrier and looper so as to obtain apredetermined relationship between the looper and needle of the machine.

9. In a sewing machine, the combination of a looper lever driven incoordination with the needle-actuating mechanism of the machine; alooper carrier pivotally mounted on the looper lever; a looper on thelooper carrier; and means including a mechanism normally locking thelooper carrier in a predetermined operating position on the looperlever, and means for moving and shifting the looper carrier and looperwith respect to the lever so as to obtain a predetermined relationshipbetween the looper and needle.

10. In a sewing machine, a looper lever driven in coordination with theneedle-actuating mechanism of the machine; a looper carrier pivotallymounted on the looper lever; a looper on the looper carrier; a manuallyoperable latch mechanism normally holding the looper carirer in apredetermined operating position on the looper lever; and threaded meansfor moving and shifting the looper carrier and looper with respect tothe looper lever so as to obtain a predetermined relationship betweenthe looper and needle, said shifting means and latch mechanism beingopel'- able independently of each other.

11. In a sewing machine, a looper lever driven in coordination with theneedle-actuating mechanism of the machine; a looper carrier comprising abar at one end pivotally mounted on the looper lever; a looper on thelooper carrier; a manually operable latch mechanism normally holding thelooper carrier in a predetermined operatin'g position on the looperlever, the said mechanism including a plunger carried by the bar andprojecting from the free end thereof, and including a latch platesecured to the end of the looper lever and having an aperture cooperablewith the plunger; and means for shifting the latch plate on the -looperlever so as to move the looper carrier to obtain a predeterminedrelationship between the looper and needle of the machine.

12. In a sewing machine, a looper lever driven in coordination with theneedle-actuating mechanism of the machine; a looper carrier comprising abar at one end pivotally mounted on the looper lever; a looper on thelooper carrier; a manually operable latch mechanism normally holding thelooper carrier in a predetermined operating position on the looperlever, the said mechanism including a plunger carried by the bar andprojecting from the free end thereof, and including a latch platesecured to the end of the looper lever, having an aperture cooperablewith the plunger; and means including a screw threaded into the looperlever and including a bifurcated arm extending from the latch plate andengaging the screw for shifting the latch plate on the looper lever soas to move the looper carrier to obtain a predetermined relationshipbetween the looper and needle of the machine.

13. In a sewing machine, a work-supporting arm extending to a pointbelow the machine needie, the said arm having a pair of apertures at itsend, and having a movable cover plate closing over one of the saidapertures; a looper lever extending through the arm, one end of thelever being located adjacent the apertures in the arm; a looper carrierpivotally mounted on the said end of the looper lever; a latchmechanism, including a manually operable member located to be accessiblefrom the aperture closed over by the cover plate, said mechanismnormally holding the looper carrier in a predetermined operatingposition on the looper lever; manually operable means accessible fromthe aperture closed over by the cover plate for shifting the loopercarrier with respect to the looper lever so as to obtain a predeterminedrelationship between the looper and the machine needle; and manuallyoperable means accessible from the aperture not closed over by the coverplate for locking the looper carrier in any shifted position.

14. In a sewing machine, a Work-supporting arm extending to a pointbelow the machine needle, the said arm having an aperture at its end,and having a movable cover plate closing over the aperture; a looperlever extending through the arm, one end of the lever being locatedadjacent the aperture in the arm; a looper carrier -pivotally mounted onthe said end of the looper lever; a vlatch mechanism, including amanually operable member located to be accessible from the aperture ofthe Work-supporting arm, said mechanism normally holding the loopercarrier in a predetermined operating position on the looper lever; andmanually operable means accessible from the aperture of thework-supporting arm, for shifting the looper carrier with respect to thelooper lever so as to obtain a predetermined relationship between thelooper and the machine needle.

FRANCIS P. TAMBURRO.

CES CITED The following references are of record in the le of thispatent:

UNITED STATES PATENTS Number Name Date 591,545 Onderdonk Oct. 12, 18971,041,652 Merritt Oct. 15, 1912 2,354,730 Ashworth et al. Aug. 1, 1944

